The rectification of a multi-phase alternating current signal into a DC current signal is well known in the art. In U.S. Pat. No. 3,284,690, there is disclosed a half cycle rectifying apparatus for rectifying a multi-phase signal. Thus, the SCRS 20 and 22 (in FIG. 1 thereof) and SCRS 52, 54 and 56 (in FIG. 2 thereof) permit half cycle rectification.
In U.S. Pat. No. 3,434,032, there is disclosed a full wave rectifying apparatus for rectifying a multi-phase signal alternating between peak-to-peak. However, the neutral signal is not used in the rectification process. Thus, the apparatus rectifies a multi-phase signal connected in a delta configuration.
In U.S. Pat. No. 4,667,282, a three-phase full wave rectifier is disclosed in FIG. 1 thereof. As disclosed in that reference (see for example, Col. 4, lines 13-26), the apparatus operates as a full wave rectifier for a low input voltage and a half wave rectifier when the input voltage is high.
Heretofore, because of the different voltage standards in different parts of the world, a manufacturer of electrical equipment that requires DC power has attempted to manufacture a universal (adaptable in many countries) power rectifier by providing for a transformer. Thus, in the countries where the voltage of the alternating current signal is high, the transformer would lower the signal to an acceptable low value where a conventional full wave rectifier can be used thereon.
Thus, it is desired as one of the objects of the present invention, to provide a universal (adaptable in many countries, especially those countries employing high voltage alternating current signal) full wave power rectifier without the need for a transformer.
Other references which may be of relevant to this application include U.S. Pat. No. 4,184,075; 4,433,368; 4,495,557; 4,654,538; and 4,665,323.